Technical Field
The present disclosure relates to a liquid administration device for administering a liquid into a living body.
Background Art
In the related art, a prefilled syringe, which is previously filled with a liquid such as a medicine, is known. In general, the prefilled syringe includes a syringe outer cylinder in which a liquid is accommodated and that is formed with a discharge port at a distal end through which the liquid is discharged, a needle tube that is provided in the discharge port of the syringe outer cylinder, a gasket that is slidable in the syringe outer cylinder, and a plunger for pressing the gasket in a distal direction.
The prefilled syringe is also used when a patient performs self administration at home. For this reason, a configuration has been proposed (for example, refer to US2011/0092915A) in which a needle tube is covered with a cover member that is biased by a spring, in order to improve safety. Such a prefilled syringe has a configuration in which, when performing administration, the skin is punctured with a needle tube protruding by pressing the cover member to the skin of an object of administration, and after the administration, the cover member is separated from the skin of the object of administration in order to cover the needle tube by advancing the cover member using the spring. With such a configuration, the needle tube is covered with the cover member except when puncturing, and therefore, erroneous puncturing is suppressed and safety is enhanced.
Since the cover member is also biased by the spring during the administration, there is a concern that, if pressing force is erroneously weakened in the middle of the administration, the cover member is moved by the spring so as to cover the needle tube which is then pulled out from a living body, and thus, it is difficult to perform administration.
In addition, in a case where an exposure restriction unit that restricts the movement of the cover member so as not to expose the needle tube again is provided in the prefilled syringe, when the cover member moves so as to cover the needle tube after the administration, if the pressing is erroneously weakened in the middle of the administration, the exposure restriction unit is operated to cover the needle tube with the cover member, and therefore, it is impossible to continue the administration regardless of being in the middle of the administration.